Driver Station not receiving code

[BrighidKHeh]

I've built the code successfully in Eclipse, and it ran successfully. When I go to the Driver Station to try and deploy the code, I receive the following error:

ERROR Unhandled exception instantiating robot org.usfirst.frc.team3871.robot.Robotjava.lang.Clas sNotFoundException: org.usfirst.frc.team3871.robot.Robot at [java.net.URLClassLoader$1.run(URLClassLoader.java: 372), java.net.URLClassLoader$1.run(URLClassLoader.java: 361)
...........

And so on and so on. Anyone else have this? If so, how did you fix it?